$OpenBSD: patch-lua_cmsgpack_c,v 1.2 2016/06/11 14:10:06 jca Exp $
--- lua_cmsgpack.c.orig	Mon Nov  5 20:14:43 2012
+++ lua_cmsgpack.c	Tue May 17 09:15:56 2016
@@ -328,7 +328,11 @@ static void mp_encode_lua_type(lua_State *L, mp_buf *b
 
 /* Convert a lua table into a message pack list. */
 static void mp_encode_lua_table_as_array(lua_State *L, mp_buf *buf, int level) {
+#if LUA_VERSION_NUM <= 501
     size_t len = lua_objlen(L,-1), j;
+#else
+    size_t len = lua_rawlen(L,-1), j;
+#endif
 
     mp_encode_array(buf,len);
     for (j = 1; j <= len; j++) {
@@ -687,14 +691,14 @@ static int mp_unpack(lua_State *L) {
 
 /* ---------------------------------------------------------------------------- */
 
-static const struct luaL_reg thislib[] = {
+static const struct luaL_Reg thislib[] = {
     {"pack", mp_pack},
     {"unpack", mp_unpack},
     {NULL, NULL}
 };
 
 LUALIB_API int luaopen_cmsgpack (lua_State *L) {
-    luaL_register(L, "cmsgpack", thislib);
+    luaL_openlib(L, "cmsgpack", thislib, 0);
 
     lua_pushliteral(L, LUACMSGPACK_VERSION);
     lua_setfield(L, -2, "_VERSION");
